The present invention relates to apparatus for measuring the angular velocity of a rotating body, more particularly to apparatus which uses a difference in frequencies or phases between microwaves propagated clockwise and counterclockwise through a closed-loop microwave propagation path.
For the measurement of the angular velocity of a rotating body, a mechanical gyro which uses a spinning rotor to cause inclination of its axis in accordance with the angular velocity of the rotating body is known. Known also is a laser gyro which uses laser lights propagated clockwise and counterclockwise through a predetermined optical path for optical interference with each other to provide optical interference stripes indicative of the phase difference corresponding to the angular velocity of the rotating body.
The former gyro, however, needs a power generator such as an electric motor which enables the rotor to spin at a high speed and hence it becomes undesirably large in size.
The latter gyro, although not so large in size, needs a very complicated electronic circuit which converts the optical interference stripes indicative of the phase difference caused by the interference between the clockwise and counterclockwise laser lights into electric signals.